简单的定时任务可以直接通过Spring自带的task来实现,复杂的定时任务则可以通过集成Quartz来实现。
Timer:这是java自带的java.util.Timer类,这个类允许你调度一个
java.util.TimerTask任务。使用这种方式可以让你的程序按照某一个频度执行,但不能在指
定时间运行。一般用的较少。
 Quartz:这是一个功能比较强大的的调度器,可以让你的程序在指定时间执行,也
可以按照某一个频度执行,配置起来稍显复杂。
Task是由Spring自带的定时器,使用方便、简单
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.time</groupId>
    <artifactId>TimeTask</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <!-- 声明项目配置依赖编码格式为 utf-8 -->
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <fastjson.version>1.2.24</fastjson.version>
    </properties>

    <dependencies>
        <!--定时器依赖 -->
        <dependency>
            <groupId>org.quartz-scheduler</groupId>
            <artifactId>quartz</artifactId>
            <version>2.2.1</version><!--$NO-MVN-MAN-VER$-->
        </dependency>
        <!-- 该依赖必加,里面有sping对schedule的支持 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
        </dependency>
        <!--必须添加,要不然会出错,项目无法启动 -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
        </dependency>
        
        <!--devtools热部署 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
            <scope>true</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>
package com.tszr.time.job;

import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Configuration
@Component
@EnableScheduling
public class ScheduledTask {
    private Logger log = LoggerFactory.getLogger(ScheduledTask.class);

    @Scheduled(cron = "0 0/1 * * * ?")
    public void testOne() {
        log.info("每分钟执行一次");
    }

    @Scheduled(fixedRate = 30000)
    public void testTwo() {
        log.info("每30秒执行一次");
    }

    @Scheduled(cron = "0 0 1 * * ?") // 表示每天凌晨一点执行
    public void initTask() {
        // 执行任务
        log.info("执行任务" + new Date());
    }
}
package com.tszr.time;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling
public class TimeSpringApplication {
    public static void main(String[] args) {
        SpringApplication.run(TimeSpringApplication.class,args);
    }
}